1. Field of the Invention
This invention pertains to substituted .beta. amino acid derivatives which inhibit platelet aggregation.
2. Related Art
Fibrinogen is a glycoprotein present as a normal component of blood plasma. It participates in platelet aggregation and fibrin formation in the blood clotting mechanism.
Platelets are cellular elements found in whole blood which also participate in blood coagulation. Fibrinogen binding to platelets is important to normal platelet function in the blood coagulation mechanism. When a blood vessel receives an injury, the platelets binding to fibrinogen will initiate aggregation and form a thrombus. Interaction of fibrinogen with platelets occurs through a membrane glycoprotein complex, known as gpIIb/IIIa; this is an important feature of the platelet function. Inhibitors of this interaction are useful in modulating or preventing platelet thrombus formation.
It is also known that another large glycoprotein named fibronectin, which is a major extracellular matrix protein, interacts with fibrinogen and fibrin, and with other structural molecules such as actin, collagen and proteoglycans. Various relatively large polypeptide fragments in the cell-binding domain of fibronectin have been found to have cell-attachment activity. (See U.S. Pat. No. 4,517,686; 4,589,881; and 4,661,111). Certain relatively short peptide fragments from the same molecule were found to promote cell attachment to a substrate when immobilized on the substrate or to inhibit attachment when in a solubilized or suspended form. (See U.S. Pat. Nos. 4,578,079 and 4,614,517).
In U.S. Pat. No. 4,683,291, inhibition of platelet function is disclosed with synthetic peptides designed to be high affinity antagonists of fibrinogen binding to platelets. U.S. Pat. No. 4,857,508 discloses tetrapeptides having utility as inhibitors of platelet aggregation.
Other synthetic peptides and their use as inhibitors of fibrinogen binding to platelets are disclosed by Koczewiak et al., Biochem. 23, 1767-1774 (1984); Plow et al., Proc. Natl. Acad. Sci. 82, 8057-8061 (1985); Ruggeri et al., Ibid. 83, 5708-5712 (1986); Ginsberg et al., J. Biol. Chem. 260 (7), 3931-3936 (1985); Haverstick et al., Blood 66 (4), 946-952 (1985); and Ruoslahti and Pierschbacher, Science 238, 491-497 (1987). Still other such inhibitory peptides are disclosed in EP Patent Applications 275,748 and 298,820.
U.S. Pat. No. 4,879,313 discloses compounds useful as inhibitors of platelet aggregation having the formula: ##STR1## wherein x=6 to 10,
y=0 to 4, PA1 Z=H, COOH, CONH2 or Cl-6 alkyl, PA1 R.sup.2 is selected from the group consisting of hydrogen, lower alkyl radicals, lower alkenyl radicals, lower alkynyl radicals, alicyclic hydrocarbon radicals, aromatic hydrocarbon radicals, wherein said radicals are optionally substituted with hydroxy, lower alkoxy, lower alkyl, halogen, nitro, cyano, azido, ureide, ureylene, carboxyl or carbonyl derivatives, trifluoromethyl, acyloxy, alkylthio, arylthio, alkylsulfenyl, arylsulfenyl, alkylsulfonyl, arylsulfonyl, amino, alkylamino, trialkylsilyl, aminosulfonyl, dialkylamino, alkanoylamino, aroylamino, phenyl, naphthyl,lower alkynyl which are optionally substituted with one or more of the following: halogen, nitro, lower alkoxy, lower alkyl, trialkyl silyl, azide and phenyl. PA1 W is selected from the group consisting of hydrogen, lower alkyl radicals, lower alkenyl radicals, lower alkynyl radicals, alicyclic hydrocarbon radicals and aromatic hydrocarbon radicals, wherein said radicals are optionally substituted with hydroxyl, lower alkoxy, lower alkyl, halogen, nitro, amino, acyloxy, and phenyl and naphthyl which may be optionally substituted with halogen, nitro, lower alkoxy, and lower alkyl; PA1 Z, Z', Z" are independently selected from the group consisting of hydrogen, lower alkyl radicals, halogen, alkoxy, cyano, sulfonyl, carboxyl, alkoxycarbonyl, and hydroxyl radicals; PA1 q is an integer from 0 to about 6; and PA1 with the proviso that when A is trimethylene and q is 0 then R.sub.2 is not hydrogen, methyl radical or phenyl radical and also that when A is trimethylene and q is 1 then R.sub.2 is not hydrogen. PA1 R.sub.2 is selected from hydrogen, lower alkyl radicals of 1 to about 6 carbon atoms, lower alkenyl radicals of 2 to about 6 carbon atoms, lower alkynyl radicals of 2 to about 8 carbon atoms, alicyclic hydrocarbon radicals of 3 to 6 carbon atoms, aromatic hydrocarbon radicals, wherein said radicals are optionally substituted with hydroxyl, lower alkoxy, lower alkyl, halogen, nitro, cyano, azido, ureide, ureylene, amino, trialkylsilyl, alkylsulfonyl, phenylsulfonyl, trifluoromethyl, acetoxy, acetylamino, benzoylamino, carbonyl, carboxyl derivatives, alkylsulfonyl amino, and phenylsulfonyl amino; PA1 A is selected from lower alkyl radicals of 1 to about 6 carbon atoms, lower alkenyl radicals of 2 to about 6 carbon atoms, lower alkynyl radicals of 2 to about 4 carbon atoms, and alicyclic hydrocarbon radicals of 3 to about 5 carbon atoms, wherein said radicals are optionally substituted with hydroxyl, lower alkoxy, halogen, alkylthio and amino; PA1 W is selected from hydrogen,lower alkyl radicals of 1 to about 6 carbon atoms, lower alkenyl radicals of 2 to about 6 carbon atoms, alicyclic hydrocarbon radicals of 3 to about 6 carbon atoms, and aromatic hydrocarbon radicals of 6 to about 12 carbon atoms, wherein all of said radicals are optionally substituted with hydroxyl, lower alkoxy, lower alkyl, halogen, nitro, amino, and acyloxy; PA1 Z, Z', Z" are independently selected from the group consisting of hydrogen, halogen, alkoxy, cyano, sulfonyl, carboxyl, alkoxycarbonyalkyl, alkoxycarbonyl and lower alkyl radicals; and PA1 q is an integer from 0 to about 6. R.sup.1 is preferable hydrogen: PA1 wherein R.sub.1 is selected from hydrogen, lower alkyl radicals, lower alkenyl radicals, aromatic hydrocarbon radicals, alicyclic hydrocarbon radicals, benzyl radicals, phenethyl radicals, wherein all of said radicals are optionally substituted with halogen, lower alkoxy, hydroxy and lower alkyl; PA1 R.sup.2 is selected from hydrogen, lower alkyl radicals, lower cycloalkyl radicals, lower alkenyl radicals, lower alkynyl radicals, phenol radicals, phenyl radicals, naphthyl radicals wherein each radical may have one or more substituents selected from the group consisting of halogen, lower alkyl, lower alkoxy, carboxyl derivatives, nitro, cyano, azido, ureido, ureylene, alkylcarbonyloxy, hydroxyl, alkylamino, alkoxycarbonyl, trialkylsilyl, alkoxyimino, alkylsulfonyl, phenylsulfonyl, alkylsulfonyl amino, phenylsulfonyl amino and amino; PA1 A is selected form lower alkyl radicals, lower cycloalkyl, and lower alkenyl radicals; PA1 W is selected from the group consisting of hydrogen and lower alkyl radicals; PA1 Z, Z', Z" are independently selected from the group consisting of halogen, hydrogen, and lower alkoxy, and alkoxycarbonyl, and alkoxycarbonylmethyl, and lower alkyl radicals; PA1 q is an integer from 0 to about 6. R.sup.1 is preferably hydrogen, lower alkyl, benzyl and phenyl. More preferably R.sup.1 is hydrogen. PA1 1. ester (COOR) Wherein R can be lower alkyl, alicyclic hydrocarbon radical or aromatic hydrocarbon radical, PA1 2. amide (CONR'R") Wherein R' and R" are independently selected from the group consisting of hydrogen, linear or alicyclic hydrocarbon, aromatic hydrocarbon radical, hydroxy or alkoxy radical,
Ar=phenyl, biphenyl or naphthyl, each substituted with 1 to 3 methoxy groups, or an unsubstituted phenyl, biphenyl, naphthyl, pyridyl or thienyl group, and PA2 Asp=aspartic acid residue. PA2 R.sup.2 is preferable hydrogen lower alkyl radicals of 1 to about 6 carbon atoms and is optionally substituted as defined above. R.sup.2 is more preferably hydrogen and lower alkyl.
European Patent Application 372,486 discloses N-acyl .beta. amino acid derivatives of the formula: ##STR2## and their salts. Said compounds are useful for inhibiting platelet aggregation in the treatment of thrombosis, stroke, myocardial infarction, inflammation and arteriosclerosis, and for inhibiting metastasis.
European Patent Application 381,033 discloses amidino or guanidinoaryl substituted alkanoic acid derivatives useful for the treatment of thrombosis, apoplexy, cardiac infarction, inflammation, arteriosclerosis and tumors.
European Patent Application 445,796 discloses Acetic Acid derivatives useful as a ligand for adhesive proteins on blood platelet. As such these compounds are useful to modulate and/or inhibit platelet aggregation.